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(No Model.)

P; E. MILLS. BODY OF LEAST RESISTANCE FOR VESSELS', 8:0.

No. 514,835. Patented Feb. 13, 1894.

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UNITED STATES PATENT @FFKCE.

FRANCIS E. MILLS, OF SAN FRANCISCO, CALIFORNIA, ASSIGNORTO HORACE A.DEMING, OF SAME PLACE.

BODY OF LEAST RESISTANCE FOR VESSELS, 800.

SPECIFICATION forming part of Letters Patent No. 514,835, dated February13, 1894.

Application filed November 5, 1892. Serial No. 451,112. (No model.)

To all whom it may concern.-

, Be it known that I, FRANCIS E. MILLS, of the city of San Francisco, inthe county of San Francisco and State of California, have invented a newand Improved Form of Solid of Least Resistance, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, forming apart of this specification.

In the drawings-Figure 1 illustrates the construction embodied indevices for use entirely immersed in water or surrounded by air. Fig. 2illustrates the form when but two sides are to be subjected to theaction of the resisting fluid medium and Fig. 3 shows for' purpose ofexplanation and illustration a single compensating wedge.

The object of the invention is to produce a form of body, eitherv solidor hollow, which, with a given length and end displacement, will passthrough the air, water, or any other resisting fluid medium with thegreatest sustained velocity, and the least expenditure of power; andalso maintain a stationary position with the least anchorage, whenopposed by currents of wind or water; such form to be applied tomilitary or other projectiles shot through the air, submergedprojectiles and torpedos shot through the Water, submerged vesselspropelled under water, other uses hereinafter mentioned; and onelongitudinal half of it to boats and other floating craft partiallyimmersed in water.

To get the form required I first make a single compensating wedge, ofthe dimensions desired, and the shape represented in Fig. 3

in the accompanying drawings; that is to say,

a wedge (the bottom being'flat and level) the top of which taperslongitudinally and continuously in one direction to a thin horizontaledge, while the sides at right angles thereto taper continuously in theopposite direction to a'thin, vertical edge. Now, if this bodywereimmersed in water, pressing equally in all directions, the pressure onthe upper surface, acting alone, would tend to move itin the directionof its vertical end, while the pressure on the reverse part (the sides)would of itself tend to move it in the opposite direction; as these twoopposing forcesmeutralize each other, the body would remain stationary.But if, by some extrinsic power, this body were moved rapidly andhorizontally through the water, the upper inclined surface would impingeagainst and displace the water, while the reverse sides would constantlyrecede from it; and, as the displaced fluid could replace itself againstthe receding sides by its gravitating power alone, the replacement wouldbe so slow as to leave no counteracting pressure on the reverse parts ofthe wedge butinstead of that there would be aconstant tendency to avacuum there, which would retard its motion. vacuum, and also to restorethe equilibrium of forces which existed upon the two opposing wedgeswhen the body was stationary, I connect the two wedges by laterallyintervening sides, whose transverse planes are at all points diagonal tothe lines of taper of both. This I do by drawing a line through thelongitudinal center of the tapering surface of the upper wedge, andcutting away the rectangular half of each, transversely, from thiscentral line to the tapering lines of the bottom, all the way from oneend to the other, leaving it in the form shown in Fig. 2, that is,athree sided body, one side a being flat, horizontal, non-resistant,with its longitudinal edges 'a' tapering all the way in one direction,and two equal transversely flaring diagonal sides 1) whose line 0 ofconvergence tapers all the way in the opposite direction, the flare ofthe sides commencing at the narrow end b where they are vertical, andincreasing in degree all the way to the wide end, where they becomehorizontal, and merge into the flat bottom, each of these diagonal sidesthus making, in its In order to prevent this entire length, a transversetwist of ninety the act of displacement, the water will be deflectedspirally and relatively backward, directly into the vacuous spaces whichare be ing left between the receding portions and the surrounding fluid,not only preventing a vacuum there, but imparting the force of itsmomentum to the reverse portions of the wedge, and thus counteractingthe resistance opposed to its advance. In other words the displacementand replacement will be coincident, and reciprocal parts of the samemovement. The more rapid the displacement the more forcible will be theimpact of the displaced water as it is driven in upon the reverseportions of the wedge.

The form herein last described and shown in Fig. 2 embodies in twocontact surfaces the principles underlying the solid shown in Fig. 1,and when this half is inverted, and placed in the water with the Hatside level and even with its surface, it represents the application ofthe invention to boats and other craft partially immersed in the water.It forms that part of the hull at and below the loadwater line. Inconnection with the said hull construction it is preferred to supply akeel as shown.

In all boats now in use, the motive inertia of the water which isdisplaced and set in motion by the passage of the boat through it islost. Yet in all fast going boats, by far the greatest portion of thepropelling power is consumed in producing that motion, and most of thepower expended in producing it still resides in the momentum of thatmoving water at the instant it is being driven from the boat. In theform of hull herein described the larger portion of the displaced water,instead of being driven away from the boat, in the form of waves, totoss and vex all neighboring craft, and dash with destructive violenceagainst the shores, will be driven against the receding portions of theboat itself, in the manner and with the effect hereinbefore described,leaving shores uninjured, and its smaller neighbors undisturbed. Themomentum of the displaced water is utilized, and restores to the boat ina large measure the power consumed in displacing it; thus renderingpossible a very high rate of speed at comparatively small cost for thepower.

When the invention is to be applied to submerged projectiles, or toprojectiles shot through the air, or to any other use where the body iswholly inclosed by the resisting fiuid, I unite to the half alreadydescribed,

another half of the same dimensions and form, placing the Hat sidestogether so that their edges and ends exactly conform. This gives itfour equal longitudinal sides, each twisting ninety degrees in itsentire length, terminating and merging in two chiselform ends standingat right angles with each other, the twist of adjacent sides being inopposite directions, as shown in Fig. 1. Both ends being alike, thisbody will pass through the air, water or other fluid medium with equalease in either direction, displacing and replacing the fluid on theprinciple of a compensating wedge, as hereinbefore explained. The angleof longitudinal taper, in these Wedges respectively, may be uniform fromend to end, if desired, but to obtain the full effect of the principlethe line of taper should be a regular curve, tangential to the line ofmotion at the wide end, and continuing on a single radius to theopposite end, as shown. The reason for this lies in the fact, thatthough the progressive motion of the body through the air or water maybe very rapid, the lateral movement of the displaced fluid will becomparatively slow, and relatively toward the rear, thus throwing theculminating force of the replacement upon the rear portions of thereverse wedge, which by having the increasing angle of taper given it bythis curve will receive a greater impulse forward. For most purposes itwill be found desirable to round off the thin corners of the forwardend, (sometimes the rear end also) but this can be done withoutmaterially impairing the effect.

For submarine projectiles and torpedoes, this form would proveexceedingly effective, and of great value in the defense of sea-boardtowns. The enormous resistance opposed by the ms inertia of water to abody moving swiftly beneath its surface, has hitherto so limited thespeed and force of such projectiles, and enhanced the cost of employingthem, that the most vulnerable part of a hostile ship (that below thewater line) has been practically exempt from assault. But with aprojectile made in the form herein described, such parts could bereached with destructive effect, either by a plunging fire through theair, or a horizontal one beneath the surface of the water. Besides thosealready enumerated there are various other uses to which I propose toapply this invention. Among these, are submerged or partially immersedsupports for floating or ponton bridges, crossing rivers or waterssubject to the flux and and reflux of strong tides, to floatingstationary structures exposed to currents of water, to swinging ferryboats when crossing rapid streams, and to balloons and other structuresfor navigating the air, whether moving or stationary, to enable them toovercome the resistance of the atmosphere, or to withstand the force ofthe wind.-

For most of the uses herein mentioned itis best to make thelin es ofthetransverse sections of the body straight, but where greater buoyancywith the same longitudinal dimensions is desired, as in stationaryballoons and floats, these lines may be slightly convex withoutdetracting very greatly from the effect, such curvature being indicatedin some of the cross sectional views forming a part of Fig. 1.

Having now fully described the invention and mentioned the principaluses to which I propose to apply it, what I claim as my invention, anddesire to secure by Letters Patcut, is-

1. A body of least resistance substantially as described consistingmainly and substantially of two laterally adjoined and longitudinallyreversed wedges, connected and merged together laterally by four sideswhose transverse planes are at all points diagonal to the lines of taperof both wedges, and twist transversely ninety degrees in their entirelength, the twist of adjacent sides being in opposite directions, andall terminating in and merging into two chisel-formends which stand atright angles with each other, substantially as and for the purposesherein described.

2. A body of least resistance substantially as described which consistssubstantially of two laterally adjoined and longitudinally reversedwedges connected and merged together by four transversely twisting sidesdiagonal to the lines of taper of both, the twist of adjoiningsides-bein g ninety degrees, in opposite directions, all terminating andmerging in two chisel-form ends which stand at right angles with eachother, the longitudinal taper of the wedges, respectively,being inregular curves commencing parallel with the line of motion below theload water line flaring upward and' outward transversely from thelongitudinal center of the'inelined bottom to the load water line, theflare of'the sides commencing at the narrow and deep end, where they aresubstantially vertical, and increasing in degree all the way to the wideend, at or a little above the load water line, the flaring sides havinga transverse twist in opposite directions, substantially as and for thepurpose herein described.

4. A non-resistant device substantially as described having its adjacentsurfaces subject to the action of the resisting fluid merged at one endin a chisel form edge, sloped upward on their longitudinal meeting edgesfrom said chisel form edge to a plane atright angles thereto, and flaredor twisted continuously in opposite directions from the chisel form endtill they merge in the plane of the upper edge of the bottom slope oftheir longitudinal meeting edges substantially as set forth.

5. In a boat, or other floating craft partially immersed in water, ahull, which, at and below the load water line has the exterior formsubstantially, of two laterally adjoined and longitudinally reversedwedges, connected and merged together by flaring sides which in theirentire length are transversely diagonal to the lines of taper of both,and have a transverse twist of ninety degrees, in opposite directions,the lines of longitudinal taper being regular curves, the horizontalcurves commencing tangential to the line of the boats motion at the wideend, and continuing with a single radius to the narrow end, while thevertical taper starts parallel with the line of motion at the lowestpoint of the narrow end and continues on a single radius to the loadwater line at the wide end, substantially as and for the purpose hereindescribed.

, 6. A non resistant device substantially as described, having itsadjacent faces subject to the action of the resisting fluid merged atone end in avertical edge, and terminating at their opposite ends in acommon horizontal plane, and tapered continuously on a single radiusbetween said ends substantially as set forth.

FRANCIS E. MILLS.

Witnesses:

P. B. TURPIN, SoLoN C. KEMON.

